We had some ammonia issues so I started really rinsing his morning diapers (bc those are always the most pee'd filled). I just let the insert (normally a prefold) sit in the toilet for awhile then spray it off & into the pail it goes & it has helped tremendously. Also maybe skip the detergent in the first cycle?! We do a warm rinse, hot wash with detergent & oxiclean (which includes a soak & extra rinse) and then a cold rinse. I have read other people have had success adding more detergent.